Annunciator.



V. DURBIN.

ANNUNCIATOR.

APPLICATION FILED JUNE 14. 1918.

1,288,535. Patented Dec. 24, 1918.

wb'fimess vgmg 0 VERNON DURBIN, OF BROOKLINE, MASSACI-IUSETTS, ASSIGNOR TO THE HOLTZER- CABOT ELECTRIC COMPANY, OF BOXBURY, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

ANNUNCIATOB.

Application filed. June 14, 1918.

Z '0 all whom it may concern.-

Be it known that I, VERNON DURBIN, a citizen of the United States, residing at Brookline, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in Annunciators; and I do hereby declare the following to be a full, clear, .and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to an improvement in annunciators. The object of the invention is to improve and simplify the construction of annunciators in order to reduce the cost of production thereof, and in order to increase their efficiency and dura- 'bility. To the accomplishment of this object, the improved annunciator of the present invention consists in the structure hereinafter described and pointed out in the claims.

The preferred form of .the invent-ion is illustrated in the accompanying drawing, which is a perspective view of the improved annunciator. The movable or operative parts of this annunciat-or are supported on a frame or casing 5, which consists of a bottom plate 6 having two ends formed at rightangles thereto, a rear end 7 and a front end 8. Upon these upright ends of the frame 5 is rotatably mounted the armature shaft 10. The forward end of the shaft 10 is pointed and pivoted in a recess in the front end 8 of the frame 5 and the rear end of the shaft 10 is also pointed and is received in a correspondingly shaped hole in an adjustment nut 11 which screws into the rear wall 7 of the frame 5. By adjusting the nut 11 in the wall 7, the end-play of the armature shaft may be regulated. The armature shaft supports at its forward end the target 13. A stop pin 14 projecting from the forward side of the target is adapted to contact with shoulders 15 and 16 formed in the upper part 17 of the front wall 8 of the frame 5, and thereby determines the operative and inoperative positions of the target. The magnet for actuating the target is U-shaped and consists of two poles 1 9 and 20 connected by a yoke 21. The poles 19 and 20 pass through correspondingly shaped holes in the bottom plate 6 of the frame, and the yoke 21 takes up against the under side of the bottom Specification of Letters Batent.

Patented Dec. 24, 1918.

Serial No. 239,930.

plate. A screw 22 secures the magnet in place. In the top of each pole is formed an arcuate depression 23.. Each pole is separately energized, that is to say, each pole will be encircled by a separate 'coil of wire in a circuit independent of the other circuit. These circuits will be closed alternately so as to energize the poles alternately, the construction and arrangement of the parts of the annunciator being such that the energization of one pole swings the target in one direction into operative position, and the energization of the other pole swings the target in the opposite direction into inopera tive position. Either alternating or direct current may be used for energizing the poles. The armature, upon which the: energization of the poles acts in order to actu ate the target, comprises two segmentallyshaped armature plates 25 and 26 secured to the armature shaft 10. The arcuate rims 27 of these armature segments 25 and 26 swing in close proximity to the arcuate depressions 23 in the upper ends of the poles. The arcs of the segments are somewhat longer than the arcs of the depressions in the poles. It will be observed that each armature segment is provided with a projecting end 28 and a rounded portion 29. The projections 28 are oppositely disposed on the two segments; that is to say, the projecting end 28 of the segment '26 remains on one side of the armature 10, whereas the projecting end 28 of the segment 25. remains on the opposite side of the armature shaft. When the target is in vertical or dead center position, the angular relation of the projections 28 of the two segments to the perpendicular are the same. The coils for energizing the poles of the magnet are not shown on the drawing, inasmuch as they may be of usual construction and arrangement, and their connection with the pressbuttons may be as usual.

'It is assumed that the position of the target 13 as shown in the drawing is its inoperative or unannouncing position. With the target in this position it is seen that the projecting end 28 of the armature segment '26 extends upwardly, and that the cutaway portion 29 thereof is pointed downwardly toward the center of the arcuate depression in the pole 20; it is seen also that the armature segment 25 is so disposed that its thereby swinging the target 13 in a clockwise direction toward operative or announcing position. The initial pull on the projecting end 28 of the segment 26 Wlll of course be strongest and the initial movement of the target 13 will be correspondingly rapid. As the projecting end 28 of the segment 26 descends into the depression in the pole 20, however, the rotative effective of the magnetic pull on the projecting end 28 will diminish instrength, so that the movement of the target 13 will become slower. The pull of the magnetic flux on the projection 28 of the segment 26 will nevertheless continue to turn the shaft 10 in a clockwise direction, until the target 13 has'swung beyond dead center, to permit gravity to act upon it to pull it the remainder of its travel into operative or announcing position.

By the time the target has passed dead center, the arcuate edgeof the segment 26 will have substantially filled the depression in the pole 20, so that the magnetic flux will have practically no rotative effect upon the segment 26. As the target contmues to move toward announcing position, and the two ends 28 and 29 of the segment 26 become more evenly disposed on both sides of the armature shaft, the rotative effect of the magnetic flux on the segment 26 continues to diminish. Finally, before the target reaches its full announcing position, the travel of the projection 28 into the depression and the travel of the part 29 away from the depression, cause the magnetic flux to exert as great a pull, or even a greater pull, upon the part 29 than on the projection 28. This has a braking effect upon the segment 26, which at this time is moving by reason of the pull. of gravity upon the target. The

result of this braking effect of the magnetic flux upon the segment 26 as the target reaches its operative or announcing position, is to prevent the stop pin let from striking the shoulder 16 with suflicient force to cause the target to rebound. The target, therefore, swings gently into announcing position and remains there until the other pole is energized to swing the target back into its initial position. It is thus seen that the positions of the target 13 and the segment 26 on the armature shaft are such with relation to each other that the pull of the magnet upon the segment 26 acts first to move the target into such position as to be acted upon by gravity, and then acts to retard the gravity induced movement of the target. Th1s whole movement of the target 13 from its moperatlve unannouncmg posi- .tion into its operative announcing position,

thus described as occurring in distinct stages, will in reality be so rapid as to be almost instantaneous. Nevertheless, it has been found by experiment that the mode of action just described actually takes place during the progress of the target from the one position to the other, and that the desideratum of having the target move into its announcing position without the undesirable rebound so common in existing types of annunciators has been secured by fashioning and positioning the armature segments as shown and described. hen the pole 19 is energized to swing the target 13- in the reverse direction, the'same mode of operation occurs as when the target swings into its announcing position.

From the foregoing description of the construction and mode of operation of the improved annunciator of the present invention, it will be recognized that it may be manufactured cheaply, and that it will be durable and efficient in operation. The frame 5, which supports the operative parts of the annunciator, may he died out of a single piece offiat stock and then stamped or bent into the requisite shape. The holes 31 in the back wall 7, through which are passed the screws for securing the annunciator in place, and the holes in the front and rear walls for the reception of the nuts which support the forward and rear ends of the shaft 10, are punched in the frame 5 y when it is died out in blank form. In like manner the magnet is died out from a piece of flat stock, the arcuate depressions in the upper ends thereof being formed at the same time. The magnet is then bent or stamped into its U-shape. armature segments 25 and '26 may be stamped out from a piece of flat stock; as may be the target 13 also. It is thus seen that the machining requisite to place the parts of the annunciator into condition for assemblage is reduced to a minimum.

Having thus described the invention, what is claimed is:-

1. An annunciator having, in combination, a rotatable armature comprising a pair of armature segments, a pair of magnet poles for energizing the armature segments separately, and a target mounted to move with the segments, the whole being constructed and arranged so that when the poles are energized separately and alternately, the armature segments and target are swung in one direction and then in the reverse direction. I

2. An annunciator having, in combination, a rotatable shaft, a target secured thereto, a pair of armature segments secured So also, the

to the shaft and a pair of magnet poles for separately energizing the armature segments, said segments being so shaped and positioned on the shaft that When either of the magnet poles is energized to actuate the segments, a movement is imparted to the target Which is rapid at first and gradually diminishes in rapidity as the target oompletes its movement.

3. An annunciator having, in combination, a rotatable armature comprising an armature segment, a magnet for energizing the segment, and a target mounted to move with the segment, the target and segment being so positioned With relation to each other that the pull of the magnet upon the segment acts first to move the target into position to be acted upon by gravity and then acts to retard the gravity induced movement of the target.

4. An annunciator having in combination, a rotatable armature shaft having tWo segments fixed thereon, each segment havinga projection and a rounded portion, a target fixed on the shaft, and a pair of magnet poles for moving the segments to rotate the shaft, the segments being so disposed with relation to the target, that the magnetic pull on the projections moves the target and the magnetic pull on the rounded portions tends to retard the movement of the target.

VERNON DURBIN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

